Fig. 1. Longitudinal/sagittal and transverse ultrasound and MR images at the level of the fetlock joint and proximal phalanx demonstrating the normal anatomic features and corresponding echogenicity pattern of the structures in this region. The white boxes on the transverseMRimages outline the anatomy on the ultrasound images that were obtained to demonstrate the normal appearance of the SSL and ISL. The white lines in the sagittal MR images denote the level of the transverse images that were obtained from proximal to distal. The white box on the first sagittal image represents how much of the anatomy may not be imaged with ultrasound if precaution is not taken to visualize under the ergot. The arrow denotes the sagittal part or dorsal bundle of the SSL. The relaxation artifact of the SSL can be identified on both sagittal MR images to varying degrees. This artifact can complicate interpretation of the MR images.
